In synthesizing methanol from natural gas, in most cases, natural gas is steam-reformed, then reformed gas containing hydrogen and carbon monoxide is generated, and methanol is then synthesized from the reformed gas. In a synthetic plant for producing methanol in the above-described manner, steam and heat required within the plant are provided by heat recovery from flue gas generated by the steam reforming and heat recovery from reformed gas and also by using heat of reaction resulting from the synthesis of methanol so that the so-called self-balance is secured at the stage of designing of the system.
On the other hand, Japanese Patent Publication (B2) No. H04-51596 discloses a method for synthesizing gasoline from methanol via dimethyl ether (DME). A reaction for synthesizing DME from methanol is an exothermic reaction, and the heat of reaction is 231 kcal equivalent to 1 kg of methanol. In addition, a reaction for synthesizing gasoline from methanol via DME is also an exothermic reaction, and the heat of reaction is 416 kcal equivalent to 1 kg of methanol.